Self-loading scrapers which are provided with a generally upright auger near the cutting edge of the scraper bowl are well known as disclosed in U.S. Pat. Nos. 3,857,190, 3,863,367, and a number of earlier patents. The auger helps to prevent jamming of material in the front of the bowl by moving some of it upwardly so that it may fall behind the auger. Such augers commonly have a shaft mounted in a bearing at the bottom of the bowl, while there is a driving connection between the upper end of the auger shaft and an auger drive means which is mounted upon a cross beam at the top of the bowl as disclosed in said U.S. Pat. No. 3,863,367.
The bearing structure which is in the bottom of a self-loading scraper bowl must be capable of functioning in an enviornment where it is constantly submerged in earth of varying degrees of fineness, and where it may be subjected to substantial impact of large rocks and the like. Accordingly, it must be extra-ordinarily well sealed against dirt which could damage the bearings; and it must be of a very rugged construction.
At the same time, installation of a complete auger assembly must be relatively simple, and must permit ready access to various parts of the assembly for purposes of repair or replacement.
The most dirt-proof lubricant seals are metal-to-metal seals of the general type disclosed in U.S. Pat. No. 3,180,648, and such seals are ineffective until a pair of elastomeric rings have been sufficiently compressed to bring the mating faces of the metal sealing rings into contact with one another. The loading of an annular seal, such as that of U.S. Pat. No. 3,180,648, requires rather uniform application of force throughout the circumference of the seal means, and this cannot be accomplished with any degree of certainty during mounting of an auger upon such a bearing structure.